Determination of soluble angiotensin-converting enzyme 2 in saliva samples and its association with nicotine.

INTRODUCTION: The Angiotensin-Converting Enzyme 2 (ACE2) is the main receptor of the SARS-CoV-2. There is contradictory evidence on how the exposure to nicotine may module the concentration of soluble ACE2 (sACE2). The aim of this study was to assess the association between nicotine and sACE2 concentrations in saliva samples. METHODS: Pooled analysis performed with data retrieved from two studies (n = 634 and n = 302). Geometric mean (GM) concentrations of sACE2, both total and relative to the total amount of protein in the sample, were compared according to sociodemographic variables and variables associated to nicotine. Multivariable linear regression models were fitted to explore the associations of sACE2 with nicotine adjusting for sex, age and body mass index. Spearman's rank-correlation coefficients were estimated between the concentrations of nicotine and cotinine, and pack-years, the concentration of relative sACE2 and the isoforms of sACE2. RESULTS: We observed a significant increase of 0.108‰ and 0.087 ng/µl in the relative and absolute salivary sACE2 GM concentrations, respectively, between the lowest and highest nicotine levels. Similar results were observed for cotinine. These associations did not change in the multivariable linear models. There was a low correlation of nicotine and cotinine concentration with the concentration of relative salivary sACE2 (rs = 0.153 and rs = 0.132, respectively), pack-years (rs = 0.222 and rs = 0.235, respectively) and with the concentration of isoform 40 KDa (rs = 0.193 and rs = 0.140, respectively). CONCLUSION: Salivary nicotine concentration seems to be limitedly associated with the concentration of sACE2.

Association between Leisure Screen Time and Emotional and Behavioral Problems in Spanish Children.

OBJECTIVE: To assess the relation between leisure screen time and emotional and behavioral problems in Spanish children aged 4-14 years. STUDY DESIGN: This cross-sectional study used a representative sample of children aged 4-14 years included in the 2017 Spanish National Health Survey (n = 4073). Emotional and behavioral problems of children were assessed through the parent-report Strengths and Difficulties Questionnaire. Daily leisure screen time in minutes was categorized as 0-59, 60-119, 120-179, and ≥180. We calculated adjusted prevalence ratios (aPR) and their 95% CIs of being at risk of developing emotional and behavioral problems. Associations were adjusted for potential confounding variables. RESULTS: Children spending 180 minutes or more of daily leisure screen time compared with children spending less than 1 hour were more likely to be at risk of developing emotional and behavioral problems: aPR≥180: 2.19 (95% CI 1.53-3.14), emotional symptomology: aPR≥180: 2.09 (95% CI 1.37-3.18), conduct problems aPR≥180: 1.85 (95% CI 1.34-2.54), peer problems aPR≥180: 1.78 (95% CI 1.15-2.75), and to behave less prosocially: aPR≥180: 2.20 (95% CI 1.43-3.37). CONCLUSIONS: We have found significant associations between daily leisure screen time and emotional and behavioral problems in Spanish children between 6 and 14 years of age. However, these findings should be confirmed in cohort studies, so institutions might consider including screen time as a new risk factor for children.

Association of screen time and sleep duration among Spanish 1-14 years old children.

BACKGROUND: Due to the change in screen time usage in the last decade, there is needed to add more evidence about the relationship of screen time and sleep duration. OBJECTIVE: To assess the association between screen time and sleep duration among Spanish children between 1 and 14 years old. METHODS: We used data from the 2017 Spanish National Health survey, conducted on a representative sample of the Spanish population. We categorised daily leisure screen time as 0-59, 60-119, 120-179, and ≥180 minutes. We classified sleep duration, depending on the age, as proper sleep duration and short sleep duration. We calculated unadjusted, and adjusted prevalence ratio (PR) and 95% confidence interval (CI) of short sleep duration according to daily leisure screen time after adjusting for potential confounders. PR's were derived from fitting generalised linear models with Poisson distribution and robust variance. RESULTS: Of the 5517 Spanish children aged 1-14 years, 44.3% spent 120 minutes or more of daily leisure screen time and 23.6% had short sleep duration. 24.5% and 28.2% of children spending between 120 and 179 minutes and exceeding 180 minutes of daily leisure screen time suffered short sleep duration, respectively. In the adjusted model, higher patterns of daily leisure screen time were associated with short sleep duration: adjusted PR120-179  = 1.34 (95% CI 1.18, 1.54) and adjusted PR≥180  = 1.48 (95% CI 1.27, 1.73). CONCLUSIONS: Around one out of four Spanish children between 1 and 14 years old, exceeding 120 minutes of daily leisure screen time, had short sleep duration. More scientific research is needed for institutions to work on providing novel healthcare programmes that consider these new determinants of child health.

Prevalence and determinants of metabolic syndrome in Spanish salaried workers: evidence from 15 614 men and women.

OBJECTIVE: To describe the prevalence of Spanish workers with Metabolic Syndrome (MetS) and those at risk of developing MetS in 2015. METHODS: Cross-sectional study of workers (n = 15 614). We used a modified definition of the NCEP:ATPIII criteria for MetS (we used body mass index (BMI) above 28.8 kg/m2 instead of the waist circumference criterion). We calculated the prevalence of MetS (having at least three components) and of being at risk of MetS (having one or two components). We calculated adjusted odds ratios (aOR) of MetS according to socio-economic and workplace characteristics. RESULTS: The proportions of workers with and at risk of MetS were 7.1 and 31.9%, respectively. The most prevalent criterion was having a BMI > 28.8 kg/m2 (24.1%) in men and cHDL < 40 mg/dl in women (12.9%). There were significant associations between MetS and men (aOR compared to women = 3.73, CI 95%: 3.19; 4.36); age (higher among oldest, aOR = 5.75, CI 95%: 4.37;7.56); and social class (higher among lower social class, aOR = 2.03, CI 95%: 1.65;2.48). CONCLUSION: Reducing any of the five MetS components, while taking into account the differences found by socio-economic and workplace characteristics, should be one priority for reducing MetS prevalence.

Smoking pattern and risk of lung cancer among women participating in cancer screening programmes.

OBJECTIVES: The aim of this study was to describe the smoking prevalence, the smoking pattern, and the risk of lung cancer among women who participated in a cancer screening (breast, cervical and colorectal) in Spain. METHODS: We used data from the Spanish National Health Survey of 2011-12, a cross-sectional study of the adult Spanish population from women in the age of participation in the population cancer screening. We used two definitions of the high risk of lung cancer according to the National Lung Screening Trial (NLST) criteria and the NELSON criteria. RESULTS: Participation in screening was 76.6% in breast cancer, 6.6% in colorectal cancer, and 70.3% in cervical cancer. The percentage of current smokers was 17.1 of women who participated breast cancer, 15.4 of women who participated colorectal cancer, and 26.1 of women who participated cervical cancer. According to NLST criteria, the percentage of current smokers women who had a high risk of lung cancer was 23.1 for breast cancer, 23.5 for colorectal cancer and 4.5 for cervical cancer. These figures were higher with the NELSON criteria. CONCLUSION: At least 250 000 women in Spain have a high risk of lung cancer and are participating in a cancer screening programme. These programmes might be an opportunity for implementing specific interventions aiming to reduce this risk.

Relation between tobacco control policies and population at high risk of lung cancer in the European Union.

INTRODUCTION: Lung cancer accounts for nearly 2 million deaths per year worldwide, the majority of cases due to smoking as the main risk factor associated. The aim of this study was to assess the relation between the level of implementation of tobacco control policies and the population at high risk of lung cancer in the European Union (EU). METHODS: The Special Eurobarometer 458 "Attitudes of Europeans towards tobacco and electronic cigarettes", conducted in 2017, and the Tobacco Control Scale (TCS) 2010, 2013, and 2016 were the sources of our data. High risk of lung cancer was defined by the inclusion criteria in the National Lung Screening Trial (NLST) and the Dutch-Belgian Lung Cancer Screening Trial (NELSON), the largest lung cancer screening trials carried out in the US and the EU. We calculated Spearman's rank correlation coefficients (rsp) and fitted multilevel generalized linear mixed models using the quasi-Poisson family to assess the correlation at the national level and analyze the association at the individual level, respectively, between the scores in the TCS (higher scores means better implementation of tobacco control policies) and the proportion of individuals at high risk of lung cancer in member states of the EU. RESULTS: The scores in the TCS 2010 were statistically negatively correlated with the current proportion of ever and former smokers at high risk according to NELSON criteria (-0.41; 95%CI -0.68, -0.04 and -0.49; 95%CI -0.73, -0.13, respectively). We observed statistically significant inverse associations between the scores in the TCS 2010 for the highest quartiles and the proportion of individuals at high risk of lung cancer according to both criteria. Non-statistically significant negative correlations and inverse associations were observed with other TCS. CONCLUSION: There is a lag between the implementation of tobacco control policies and the reduction of the rates of high risk of lung cancer. Member states should reinforce comprehensive tobacco control policies to reduce the population at high risk of lung cancer in the EU.

Measuring precarious employment in Europe 8 years into the global crisis.

BACKGROUND: The objective of this study is to describe the prevalence of precarious employment in the European Union (EU) using a multidimensional approach, 8 years into the economic crisis (2014). METHODS: We use data from the Flash Eurobarometer 398 among salaried workers (n = 7702). We calculated the proportion and its 95% confidence intervals (CI 95%) for each of the precarious employment dimensions (not having the ability to exercise rights, vulnerability, disempowerment and temporariness), the prevalence of precarious employment (presenting at least one dimension) and the proportion of workers presenting one, two, three or four dimensions. RESULTS: Two out of three workers had a precarious employment. The prevalence of precariousness was higher in Eastern (72.64%; CI 95%: 61.78; 81.34) than in Nordic European countries (51.17%; CI 95%: 44.30; 58.00). The most prevalent dimension was not having the ability to exercise rights (42.39%). CONCLUSIONS: Precarious employment is an important social determinant of health. Therefore, the EU policy-makers should take into consideration the new forms of employment and legislate accordingly.

Attitudes towards tobacco product regulations and their relationship with the tobacco control policies.

The objective of this work is to describe the acceptability of some tobacco products regulations and to explore their relation with tobacco control legislation levels in Europe. We used data on tobacco control activities in Europe in 2007, 2010 and 2013 measured by the Tobacco Control Scale (TCS) and data regarding attitudes about tobacco control regulations (i.e. adding picture health warnings on all packages of tobacco products or increasing taxes on tobacco products) from the Special Eurobarometer of 2009, 2012 and 2014 (n = 80,831). We calculated the prevalence ratio of favorable attitudes towards tobacco products restrictions in the reference year 2009 vs. the most current year (i.e. 2009 vs 2014), and the effect of previous TCS scores on the attitudes towards tobacco products regulations adjusted for sociodemographic variables. Strong support for the studied tobacco products regulations, which modestly increased over time, was observed. A positive relation was generally observed between TCS scores and support for the studied tobacco products regulations at both the ecological and individual level. A positive correlation was found between TCS scores and support for increasing taxes on tobacco products (rsp:0.29; 95%CI: 0.10, 0.48) at the ecological level, while at the individual level, the positive association was more remarkable in the case of support for adding large health warning labels to packaging. In conclusion, support for the studied tobacco products regulations were positively related with European tobacco control levels of implementation both at the ecological and individual level.

Smartphone use by children in fast food restaurants in Barcelona (Spain): a direct observation study.

OBJECTIVE: To explore the use of smartphones at mealtimes by children in fast food restaurants in the city of Barcelona and to assess the variables associated with this use. METHOD: A cross-sectional study was carried out. Data from 1616 children of estimated ages between 4 to 10 years were collected in fast-food restaurants in the ten districts of Barcelona between October 2021 and July 2022. The percentage of smartphone use, overall and according to covariates, were calculated. Chi-squared and Fisher's exact tests, and crude and adjusted Poisson regression models with robust variance, were carried out to assess the association between use and covariates. RESULTS: Direct observation revealed that in 28.1% of meals with children at fast food restaurants, children used smartphones. Smartphone use was significantly higher in older children if their caregivers were younger than 30 years and when there was no caregiver-child interaction. In the adjusted model, higher patterns of smartphone use were associated with older children (aPR [95% CI]: 1.36[1.20-1.55]) and younger parents (aPR [95% CI]: 1.38[1.09-1.73]). CONCLUSIONS: Almost one in three meals with children at fast-food restaurants in Barcelona involves smartphone use. This finding underlines the importance of raising awareness of responsible screen use and promoting healthier environments for children at mealtimes.

Specific biomarker comparison in current smokers, e-cigarette users, and non-smokers.

INTRODUCTION: This study aims to address the existing gap in the literature, while adding evidence, by comparing tobacco-specific biomarkers (cotinine and nitrosamines: NNK, NNAL, NNN), and other biomarkers of e-cigarette use (humectants: glycerol, 1,2-PD, 1,3-PD) according to five study groups. METHODS: A pooling analysis including two different studies was conducted. In both analyses, we took saliva samples from smokers (n = 409) and non-smokers (n = 154), dual tobacco and e-cig users (n = 92), exclusive e-cig user with nicotine (n = 158), and exclusive e-cig users without nicotine (n = 38). We analyzed and compared the geometric means (GM) and geometric standard deviations (GSD) of the concentration of tobacco-specific biomarkers, and e-cigarette biomarkers among groups. We used log-linear models adjusted for sex and age to model the change percentage and their 95% confidence intervals. RESULTS: Cotinine was significantly higher in nicotine consumers and in e-cigarette users without nicotine when compared to non-smokers. TSNAs were generally significantly lower in non-smokers and higher in nicotine consumers. NNN and NNAL were lower in e-cigarette users with nicotine comparted to smokers, and NNN was higher in e-cigarette users without nicotine when compared to non-smokers. No differences were found in humectant biomarkers between e-cigarette groups. CONCLUSIONS: Although there was a reduction in TSNAs in e-cigarette exclusive users compared to smokers, and a reduction of cotinine concentrations in e-cigarette exclusive users without nicotine compared to smokers, there are still high levels of these biomarkers when compared to non-smokers, which may be a clue towards the harmful effect of e-cigarettes.

Variation in Nicotine Metabolization According to Biological Factors and Type of Nicotine Consumer.

This study aims to describe the nicotine metabolite ratio among tobacco smokers and electronic cigarette (e-cigarette) users and nonusers. We analyzed pooled data from a longitudinal and a cross-sectional study of the adult population from the city of Barcelona. The final sample included information on 166 smokers, 164 e-cigarettes users with nicotine, 41 e-cigarette users without nicotine, 95 dual users (users of both products), and 508 nonusers. We used log-linear models to control for the potential confounding effect of the daily number of cigarettes smoked. Salivary nicotine metabolic rate assessment included the rate of nicotine metabolism (cotinine/nicotine) and the nicotine metabolite ratio (trans-3'-hydroxycotinine/cotinine). Exclusive users of e-cigarette without nicotine have the lowest rate of nicotine metabolism (Geometric mean: 0.08, p-values < 0.001) while cigarette smokers have the highest (Geometric mean: 2.08, p-values < 0.001). Nonusers have lower nicotine metabolic rate than cigarette smokers (Geometric means: 0.23 vs. 0.18, p-value < 0.05). Younger individuals (18−44 years) have a higher rate of nicotine metabolism than older individuals (45−64 years and 65−89) (Geometric means: 0.53 vs. 0.42 and 0.31, respectively, p-values < 0.01) and individuals with lower body mass index (21−25 kg/m2) have a higher rate of nicotine metabolism than the rest (26−30 kg/m2 and 31−60 kg/m2) (Geometric means: 0.52 vs. 0.35 and 0.36, respectively-values < 0.01). Nicotine metabolic rates are useful biomarkers when reporting smoking status and biological differences between individuals.

Tobacco endgame in the WHO European Region: Feasibility in light of current tobacco control status.

INTRODUCTION: To assess the feasibility of developing World Health Organization (WHO) European Region countries' goals and measures in line with tobacco endgame objectives, information on the current tobacco control context and capacity is needed. The aim of this study was to assess the implementation of the Framework Convention on Tobacco Control (WHO FCTC) and MPOWER measures in the region. METHODS: In this cross-sectional study we used data from the WHO FCTC implementation reports and MPOWER from 2020 in 53 WHO European Region countries. Six domains (i.e. capacity, taxation and price policies, other national key regulations, public awareness raising and communication, tobacco use cessation, and monitoring) were formed. Subsequently, available indicators under these domains were scored and the level of implementation was computed for each country. Mann-Whitney tests were carried out to compare the scores between the group of countries with and without official endgame goals. RESULTS: Overall, implementation of the WHO FCTC with the selected indicators at the country level ranged from 28% to 86%, and of MPOWER from 31% to 96%. Full implementation was achieved by 28% of WHO FCTC Parties in the region in taxation and price policies, 12% in public awareness raising and communication, and 42% in monitoring. In capacity, tobacco use cessation and other national key regulations, none of the Parties in the region reached full implementation. Overall median WHO FCTC scores were significantly higher in countries with official endgame goals than in those without (p<0.001). CONCLUSIONS: There is unequal implementation of both WHO FCTC and MPOWER measures among WHO European Region countries. MPOWER and WHO FCTC provide all the measures for the necessary first steps, followed by innovative measures, to accomplish tobacco endgame goals.

Competencies in Basic Life Support after a Course with or without Rescue Ventilation: Historical Cohort Study.

BACKGROUND: Simplifying the international guidelines to improve skills after training and their retention over time has been one of the top priorities in recent years. The objective of our study was to compare the results of the practical skills learned during training in basic life support with and without pulmonary ventilation. METHODS: This was a comparative study of historical cohorts consisting of undergraduate students in health sciences. In one cohort, rescue breathing was performed, and in the other, it was not. The same data collection instruments were used for both cohorts: a test type examination of knowledge, data from a smart mannequin and an instructor observation grid. The means of knowledge and practical skills scores collected by the mannequin were compared using independent sample t-tests. RESULTS: 497 students were recruited without significant differences between the two cohorts. The mean scores for knowledge and skills determined by the instructor and the mannequin were statistically higher in the cohort that did not perform rescue breathing. CONCLUSION: Students who participated in basic life support training that did not include rescue breathing scored better than those who participated in training that included this skill. Training with only compressions simplifies the guidelines and increases learning and content retention.

A Two-Point Ultrasound-Guided Injection Technique for the Transversus Thoracis Plane Block: A Canine Cadaveric Study.

The transversus thoracis plane (TTP) block desensitizes the intercostal nerves that run through this plane, providing analgesia to the ventral thoracic wall. Two canine cadavers were used to assess the feasibility of the transverse approach for the TTP (t-TTP) under ultrasound guidance to inject a solution at the third and sixth intercostal spaces. Eight cadavers were used to compare the spread and number of intercostal nerves that were stained when a low volume (LV) 0.5 mL kg-1 or a high volume (HV) 1 mL kg-1 of a dye-lidocaine solution was injected into the same hemithorax, injecting the volume equally at these intercostal spaces using the transverse approach. Fisher's exact test and Wilcoxon signed-rank test were used to contrast the spread of the different volume solutions. The injectate spread along the TTP after all injections, dying a median number (range) of 3 (2-5) and 6 (5-6) nerves with LV and HV, respectively (p = 0.011). The two-point injection of HV, using the t-TTP approach, is a feasible technique that provides a consistent staining from T2 to T7 intercostal nerves. The injection of HV instead of LV increases the spread and enhances the number of stained intercostal nerves.

Association between recreational screen time and excess weight and obesity assessed with three sets of criteria in Spanish residents aged 2-14 years.

INTRODUCTION AND OBJECTIVE: Studies that assess the association between excess weight and screen time in childhood and adolescence are methodologically heterogeneous, and few studies have analysed the exposure to smartphones and tablets. Our study aimed to assess the association between daily recreational screen time and excess weight (overweight+obesity) and obesity in children aged 2-14 years residing in Spain using different sets of standards. METHODS: We conducted a cross-sectional study using data from the 2017 Spanish National Health Survey (N=4528). We assessed the prevalence of overweight and obesity applying the criteria of the World Health Organization (WHO), International Obesity Task Force (IOTF), and Orbegozo 2011 study. We categorised daily recreational screen time in minutes as 0-59, 60-119, 120-179, and ≥180. We calculated crude and adjusted prevalence ratios (aPR) of excess weight and obesity based on the daily minutes of recreational screen time with the corresponding 95% confidence intervals (95%CI). Moreover, we calculated crude and adjusted change (aΔ) in the expected number of fulfilled excess weight/obesity criteria based on the minutes of daily recreational screen time with the corresponding 95% CI. We adjusted the association analyses for potential confounders. RESULTS: We found that spending 180min or more a day of recreational screen time was associated with an increase in the adjusted prevalence of excess weight (e.g. Orbegozo 2011 aPR≥180, 1.20; 95% CI, 1.02-1.42) and of obesity (e.g. IOTF aPR≥180, 1.41; 95% CI, 1.06-1.86) as well as an increase in the adjusted number of fulfilled criteria for excess weight (aΔ≥180, 1.18; 95% CI, 1.06-1.31). CONCLUSIONS: Longer periods of recreational screen time were associated with excess weight and obesity in children aged 2-14 years. Cohort studies are required to confirm these findings, as this may be a determinant of health in children.

Compliance Surveillance of the Tobacco Control Legislation in a Spanish Region and Characterization of Passive Exposure to Tobacco Smoke and E-Cig in Children in Outdoor Spaces.

(1) Background: Exposure to environmental tobacco smoke has decreased in recent years in Spain, due to the implementation of tobacco control policies. However, there is no regulation that protects against second-hand smoke (SHS) in outdoor environments. Our goal is to describe the smoking prohibition signage in public spaces and to characterize tobacco consumption in outdoor environments describing the SHS exposure in children. (2) Methods: A cross-sectional study using direct observation was carried out with a convenience sample (n = 179) that included hospitality venues with terraces, schools and healthcare facilities in the municipality of Sant Cugat del Vallès (Barcelona, Spain). The observations were made without notifying the owners by one single field researcher between April and June 2018. The variables were evaluated by signage and signs of tobacco consumption (ashtrays, cigarette butts and presence of smokers). (3) Results: Smoke-free zone signage outside public spaces was present in 30.7% of all venues, with only 50.9% correctness. When analysing terraces of hospitality venues, in 35.8% of them there were children present with 66.7% of tobacco consumption. (4) Conclusions: Our results show a low prevalence of antismoking signage, without an impact on tobacco consumption regardless of the presence of children.

Relationship between double COVID-19 vaccine uptake and trust in effectiveness and safety of vaccination in general in 23 Member states of the European Union: an ecological study.

INTRODUCTION: The aim of this study was to assess the relationship between double COVID-19 vaccine uptake and trust in effectiveness and safety of vaccination in general in 23 European Union (EU) countries. METHODS: Ecological study. Data was retrieved from the Flash Eurobarometer 494 and Our World in Data. We estimated Pearson's correlation coefficients and fitted multiple linear regression models. RESULTS: There is a negative linear correlation between the percentage of people doubly vaccinated and the percentage of low trust in vaccine effectiveness (r = -0.48, p-value = 0.021), and the percentage of low trust in vaccine safety (r = -0.43, p-value = 0.041). There is a negative adjusted relation between the percentage of low trust in vaccine safety and the percentage of people doubly vaccinated (aß% low trust in vaccinesafety:-0.25; 95% CI: -0.49,-0.01, p-value = 0.045). CONCLUSION: An increase in health literacy of people living in certain countries in the EU may be needed to boost COVID-19 vaccine uptake.

Association between biomarkers of tobacco consumption and lung cancer risk among daily smokers.

BACKGROUND: Biomarkers of tobacco consumption may play a role in the lung cancer risk assessment. However, the role of salivary biomarkers has not been well studied. The aim of this study is to assess the use of salivary biomarkers of tobacco consumption as lung cancer screening criterion. RESEARCH DESIGN AND METHODS: Data came from the Determinants of cotinine phase 3 project (Barcelona, 2013-2014). We compared the concentrations of TSNAs, including NNAL, NNN and NNK, and cotinine, in saliva samples of 142 daily smokers from the general population according to their risk of lung cancer. High risk of lung cancer was defined as per the inclusion criteria in the US National Lung Screening Trial (NLST) and in the Dutch-Belgian lung cancer screening trial (NELSON). RESULTS: Among daily smokers accomplishing the age criterion for lung cancer screening, salivary concentrations of cotinine, NNAL and NNK adjusted for sex were significantly higher (p-value < 0.05) in daily smokers at high risk of lung cancer compared to smokers not at high risk according to both NELSON and NLST criteria. CONCLUSIONS: Saliva concentrations of cotinine, NNAL and NNK may be used as additional criteria for lung cancer screening. Further research on this topic is guaranteed.

Changes in the salivary cotinine cut-offs to discriminate smokers and non-smokers before and after Spanish smoke-free legislation.

INTRODUCTION: High levels of cotinine in non-smokers indicate passive exposure to tobacco smoke. This study aims to evaluate variations in salivary cotinine cut-offs to discriminate smokers and non-smokers before and after the implementation of smoke-free legislation (Law 28/2005 and Law 42/2010) in a sample of the adult population of Barcelona, Spain. METHODS: This longitudinal study analyzes salivary cotinine samples and self-reported information from a representative sample (n = 676) of the adult population from Barcelona before and after the approval of smoke-free legislation. We calculated the receiver operating characteristic (ROC) curves, to obtain optimal cotinine cut-off points to discriminate between smokers and non-smokers overall, by sex and age, and their corresponding sensitivity, specificity, and area under the curve. We used linear mixed-effects models, with individuals as random effects, to model the percentage change of cotinine concentration before and after the implementation of both laws. RESULTS: The mean salivary cotinine concentration was significantly lower post-2010 law (-85.8%, p < 0.001). The ROC curves determined that the optimal cotinine cut-off points for discriminating non-smokers and smokers were 10.8 ng/mL (pre-2005 law) and 5.6 ng/mL (post-2010 law), with a post-2010 law sensitivity of 92.6%, specificity of 98.4%, and an area under the curve of 97.0%. The post-2010 law cotinine cut-off points were 5.6 ng/mL for males and 1.9 ng/mL for females. CONCLUSION: The implementation of Spanish smoke-free legislation was effective in reducing secondhand smoke exposure and, therefore, also in reducing the cut-off point for salivary cotinine concentration. This value should be used to better assess tobacco smoke exposure in this population.